*{
    margin: 0;
    padding: 0;

    /* 去除列表样式 */
    list-style: none;
}
/* body弹性布局 */
body{
    display: flex;
    flex-direction: column;
    background-color: #f5f5f5;
    margin: 0 auto;

    /* 最大宽度 */
    max-width: 1500px;
}

/* header弹性声明 */
header{

    display: flex;
    flex-direction: row;

    /* width: 2000px;
    margin: 0 auto; */
}
/* banner顶部区域 */
.banner{
    flex: 0 0 80%;
    margin: 0 auto;

    background-color: yellow;
    height: 60px;
}

section{

    display: flex;
    flex-direction: row;

    /* justify-content: center; */
}

/* 分类区 */
section .category{
    flex: 0 0 10%;
    margin-left: 10%;
}

/* 图片展示区 */
section .pic_area{
    flex: 0 0 70%;

}

section .category ul li{
    height: 40px;
    line-height: 40px;
    text-align: center;

    background-color: #dcdcdc;
    border-bottom: 1px solid white;
}

section .pic_area ul{
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;

    justify-content: space-evenly;
}

section .pic_area ul li{
    flex: 0 0 30%;
    background-color: yellow;

    margin-top: 5px;
    margin-bottom: 5px;
    height: 80px;

    /* 文字居中 */
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
}
/* 
section:nth-child(1) ul li{
    background-color: aquamarine;
    width: 20%;
}

section:nth-child(2) ul li{
    background-color: aquamarine;
} */